- A model of second-order arithmetic with the choice scheme in which $\Pi^1_2$-dependent choice fails
This is a talk at the Kurt Gödel Research Center Research Seminar in Vienna, Austria, May 18, 2017.

- Computable processes which produce any desired output in the right nonstandard model
This is a talk at the special session “Computability Theory: Pushing the Boundaries” of 2017 AMS Eastern Sectional Meeting in New York, May 6-7.

- Virtual Set Theory and Generic Vopěnka’s Principle
This is a talk at the VCU MAMLS Conference in Richmond, Virginia, April 1, 2017.

- A countable ordinal definable set of reals without ordinal definable elements
This is a talk at the CUNY Set Theory Seminar, February 10, 2017.

- A set-theoretic approach to Scott’s Problem
This is a talk at the National University of Singapore Logic Seminar, October 19, 2016.

- Generic Vopěnka’s Principle at YST2016
This is a talk at the Young Set Theory 2016 Conference in Copenhagen, Denmark, June 13-17, 2016.

- Generic Vopěnka’s Principle
This is a talk at the Rutgers Logic Seminar in New Jersey, May 2, 2016.

- Computable processes can produce arbitrary outputs in nonstandard models
This is a talk at the CUNY MOPA Seminar in New York, April 13, 2016.

- Virtual large cardinals
This is a talk at Set Theory Day in New York, March 11, 2016.

- Ehrenfeucht principles in set theory
This is a talk at the British Logic Colloquium in Cambridge, UK, September 2-4, 2015.

- Indestructible remarkable cardinals
This is a talk at the 5th European Set Theory Conference in Cambridge, UK, August 24-28, 2015.

- An introduction to nonstandard models of arithmetic
This is a talk at the Virginia Commonwealth University Analysis, Logic and Physics Seminar, April 24, 2015.

- Remarkable Laver functions
This is a talk at the CUNY Set Theory Seminar, February 27, 2015.

- Kelley-Morse set theory and choice principles for classes
This is a talk at the SoTFoM II (Symposia on the Foundations of Mathematics) conference in London, UK, January 12-13, 2015.

- Choice schemes for Kelley-Morse set theory
This is a talk at the Colloquium Logicum Conference in Munich, Germany, September 4-6, 2014.

- Incomparable $\omega_1$-like models of set theory
This is a talk at the Connecticut Logic Seminar, March 31, 2014.

- Introduction to remarkable cardinals
This is a talk at the CUNY Set Theory Seminar, March 14, 2014.

- Ramsey cardinals and the continuum function
This is a talk at the CUNY Logic Workshop, February 14, 2014.

- A Jonsson $\omega_1$-like model of set theory
This is a talk at the CUNY Set Theory Seminar, November 15, 2013.

- Embeddings among $\omega_1$-like models of set theory
This is a talk at the CUNY Set Theory Seminar, October 4, 2013.

- Models of $\rm{ZFC}^-$ that are not definable in their set forcing extensions
This is a talk at the CUNY Set Theory Seminar, May 4, 2012.

- Julia sets and the Mandelbrot set
This is a talk at the City Tech Math Club, April 19, 2012.

- Indestructibility for Ramsey cardinals
This is a talk at the Rutgers Logic Seminar, April 2, 2012.

- An iPhone app for a nonstandard model of number theory?
This is a talk at the City Tech C-LAC (Center for Logic, Algebra, and Computation) Seminar, February 14, 2012.

- Forcing and gaps in $2^\omega$
This is a talk at the CUNY Set Theory Seminar, December 2nd, 2011.

- A natural model of the multiverse axioms
This is a talk at the MIT Logic Seminar, April 8, 2010.

- Gödel’s Proof
This is a talk at the United States Military Academy at West Point Mathematics Seminar, January 20, 2010.

- Making strong cardinals indestructible by $\leq\kappa$-weakly closed Prikry forcing
This was a talk at the CUNY Set Theory Seminar sometime in 2009.

### Recent Writing

- The exact strength of the class forcing theorem
- A model of the generic Vopěnka principle in which the ordinals are not $\Delta_2$-Mahlo
- A model of second-order arithmetic with the choice scheme in which $\Pi^1_2$-dependent choice fails
- Computable processes which produce any desired output in the right nonstandard model
- Virtual large cardinals

### Mathoverflow Activity

- Comment by Victoria Gitman on Does Con(ZF + Reinhardt) really imply Con(ZFC + I0)?@Stefan For some reason, I cannot click on the link.Victoria Gitman
- Comment by Victoria Gitman on Cofinality of $j(\kappa)$ for a measurability embedding $j:V\to M$ with critical point $\kappa$@AsafKaragila I edited the question to make it clearer. Maybe I will ask your version as a follow-up if you don't ask it first :).Victoria Gitman
- Comment by Victoria Gitman on Cofinality of $j(\kappa)$ for a measurability embedding $j:V\to M$ with critical point $\kappa$@AsafKaragila I should have done a better job stating my question clearly. I wanted to know precisely what Yair answered: whether there are models where $\text{cf}(j(\kappa))$ is smaller than the size of $j(\kappa)$. Your interpretation of the question is very interesting as well, but I think much harder to answer.Victoria Gitman

- Comment by Victoria Gitman on Does Con(ZF + Reinhardt) really imply Con(ZFC + I0)?
### Cantor’s Attic

- StableAdded stable ordinals. New page==$f$-Stable Ordinals== An ordinal $\alpha$ is $f$''-stable'' for a function $f$ such that $\alpha\leq f(\alpha)$ iff $L_{\alpha}\preceq_{1}L_{f(\alpha)}$. For example: The smallest $\Pi_{0}^1$-Reflective ordinal is (+1)-stable. ==$\beta$-Stable Ordinals== An ordinal $\alpha$ is $\beta$''-stable'' for an ordinal $\beta$ such that $\alpha\leq\beta$ iff $L_{\alpha}\preceq_{1}L_{\beta}$. An ordinal $\alpha$ is ''stable'' iff $L_{\alpha}\preceq_{1}L_{\omega_{1}}$. The smallest stable […]Zetapology
- User talk:Ordnials← Older revision Revision as of 02:16, 24 August 2017 Line 1: Line 1: Hi! Zetapology speaking. I would love it if we could come into contact in order to get this website back on the rails. Hi! Zetapology speaking. I would love it if we could come into contact in order to get this website […]Zetapology
- User talk:OrdnialsCreated page with "Hi! Zetapology speaking. I would love it if we could come into contact in order to get this website back on the rails." New pageHi! Zetapology speaking. I would love it if we could come into contact in order to get this website back on the rails.Zetapology
- User:ZetapologyCreated page with "Hi! I'm 14, and I love set theory and model theory. I can't yet understand all cardinal concepts, but I at least understand indescribable cardinals, reflective cardinals, and..." New pageHi! I'm 14, and I love set theory and model theory. I can't yet understand all cardinal concepts, but I at least understand […]Zetapology
- IndescribableMostly finished the page. ← Older revision Revision as of 18:12, 23 August 2017 (One intermediate revision by the same user not shown)Line 1: Line 1: {{DISPLAYTITLE:Indescribable cardinal}} {{DISPLAYTITLE:Indescribable cardinal}} +A cardinal $\kappa$ is ''indescribable'' if it holds the reflection theorem up to a certain point. This is important to mathematics because of the concern for […]Zetapology

- Stable